There are many circumstances where poultry must be treated such as by administration of therapeutic agents. There are many therapeutic agents which are used in the raising of poultry: vaccines, competitive exclusion products, vitamins, minerals, medicaments and many others. A number of such therapeutic agents must be protected from environmental effects while being delivered to the poultry.
In particular, poultry are required to be immunized against various diseases and the type of vaccine used for each disease dictates its method of administration. Vaccines may be administered in the hatchery by injection at the time of sorting of the hatchlings from the incubator into holding or transporting trays. Live vaccines may also be administered once the hatchlings are established in their brooding areas in the form of aqueous suspensions, either sprayed on feed or added to the drinking water.
Examples of live vaccines that are used to immunize poultry include viral vaccines such as Hemorrhagic Enteritis Virus (HE), Infectious Bursal Disease Virus (IBD) and Newcastle Disease Virus (ND). Such vaccines are, at present, comprised of an attenuated strain of the virus in a suitable carrier for administration. Other viral vaccines include Infectious Bronchitis, Infectious Laryngotracheitis, Mycoplasma sp., and Pneumoviruses. Live bacterial vaccines, such as Salmonella vaccine, and protozoan vaccines, such as coccidiosis vaccine, are also used to immunize poultry.
One method of administering vaccine in the hatchery is through the use of a spray cabinet, which is utilized to spray the hatchlings with a liquid form of the vaccine. A flat or tray of hatchlings usually containing about 100 birds is placed in the spray cabinet and a predetermined dose of liquid vaccine is sprayed directly on the birds. It is expected that as the birds preen they will ingest the vaccine from their feathers. This method suffers some drawbacks in that uniform exposure of all of the hatchlings may not be easily achieved. In addition, as the birds are being sprayed with a water-suspended vaccine, there is a risk that some hatchlings may be chilled more than others leading to the staggering of vaccine uptake or loss of uniform exposure. Moreover, chilled hatchlings increase early mortality.
In my previous patent application WO 05099617 published Oct. 27, 2005 I described a soft gel delivery system for treating poultry hatchlings in a hatchling tray, in particular, an apparatus for immunizing poultry hatchlings against coccidiosis utilizing a soft gel vaccine. While the apparatus was useful in the hatchery, once the poultry are established in the barn, such apparatus is not easily used as a delivery system. Furthermore, if a soft gel used to treat poultry in a barn is not sufficiently sticky, the gel beadlets can more easily roll off the feathers of the birds onto the floor, thereby reducing the availability of the beadlets for the birds' consumption.
One common method of immunization in the barn involves the use of on-feed spray administration while the birds are feeding. A vaccine using water as a carrier is sprayed onto the feed to be provided to the poultry. The use of on-feed spray administration requires large doses of vaccine to overcome waste. Uniform exposure of the flocks to the vaccine cannot always be achieved. Although coccidia, for example, can be sprayed on feed, viral and bacterial vaccines that are highly attenuated are not hardy enough to withstand the dry surfaces of feed.
Vaccine may also be administered through the use of drinking water systems or through water proportioning systems including automatic fountains and automatic water medicator or proportioners. However, given the susceptibility of viral vaccines to chlorine and other disinfectants commonly used in poultry barns, the water lines have to be cleaned or flushed before administration of the vaccine. Additionally, administration of the vaccine through the water lines requires that after administration, the water lines must remain chlorine free sometimes for up to 24 hours to allow the safe consumption of the rest of the vaccine.
Thus, there remains a need for a simplified means for administration of therapeutic agents in soft gel form to poultry beyond the hatchling stage, where the administration of such therapeutic agent must wait until the negating effect of the maternally derived antibodies (MDA) have waned or disappeared.